You're truly never too young or too old to protect your heart. "The buildup of plaque in your arteries can silently start as early as your late teens and early 20s," explains Jennifer H. Mieres, M.D., professor of cardiology and population health and senior vice president, office of community and public health, at the North Shore-LIJ health system. Lower your odds of developing heart disease by keeping an eye on these key factors and lifestyle habits in your 30s, 40s, 50s, and beyond.

Having trouble sticking to a workout routine? Don't give up! Research suggests that it takes 66 days—not just a week or two—for exercise to feel automatic. Our fitness pros offer six simple strategies to keep you moving in the meantime.

Teens and Sex: Stop Worrying and Start Talking

It's easy to get the impression in today's highly sexualized culture that every teenager in America is having sex.

Don't believe it. The reality is that most teenagers in high school are not having sexual intercourse. According to the most recent data available from the U.S. Centers for Disease Control, some 49 percent of high school boys and 48 percent of high school girls have had sexual intercourse. This means that high school students who are not sexually experienced are actually in the majority.

It's also easy to get the impression that there is little, if anything, anyone -- and especially parents-- can do to stop teenagers from having sex. Don't believe that either. The percentage of sexually active teens aged 15 to 19 has actually decreased by 11 percent since 1991. Somebody must be doing something right.

And thank goodness. The fact is teens who engage in early sexual intercourse are more likely to do poorly at school, use alcohol and illicit drugs, and smoke cigarettes, than those who don't.

There is, of course, the risk of teenage pregnancy. Each year, one in 10 girls under the age of 20 -- one million every year -- becomes pregnant. Forty percent of these pregnancies will end in abortion, 10 percent in miscarriage, and 50 percent in live births.

Becoming a teen mom makes it less likely that the girl will ever finish high school, get a good job, and get married or, if she does get married, stay married. Becoming a teen dad can be just as devastating to a boy's future.

But even if teenagers were able to avoid sexually transmitted diseases or teenage pregnancy, it still wouldn't be a good idea for them to be having sex. Sex is a wonderful and marvelous activity, provided it is engaged in within its proper context. Two 14-year-olds having sex in the back seat of a car is hardly the proper context.

Teenage sexual activity brings with it the potential for tremendous heartbreak. Teens are simply not mature enough to handle the intense emotions that go along with sexual activity -- no matter how "in love" they profess to be.

Besides, what parents want most for their teens is not simply for them to avoid the negative consequences associated with high-risk behaviors, like early sexual activity, but for them to lead a fulfilling and enriching life.

As Karen Pittman, senior vice president of the International Youth Foundation, has put it, "What parent on earth wants to say, 'I am so proud of my kid. You know, she's 15, and hasn't gotten pregnant and hasn't stabbed anyone. My 15-year-old son hasn't been in jail yet, and he wears a condom.'"

So what's a parent to do? Research consistently indicates that parents who are successful in helping their teens refrain from sexual activity do two things: They talk to their kids about sex, and they monitor their teens' behavior.

Unfortunately, many parents are reluctant to talk with their teens about sex. According to researcher Marcela Raffaelli, PhD, assistant professor of psychology, and her colleagues at the University of Nebraska at Lincoln, nearly half of teens report never having had even one good talk with their mothers about any sexual topic. Seventy percent said they had never had a good talk with their fathers about sex.

Yet most teens actually want their parents to talk to them about sex. According to a survey by the Henry J. Kaiser Foundation, when asked who they would be most likely to ask to get information about how to prevent pregnancy, 71 percent of 13- to 15-year-olds said they would ask their parents.

Sixty-three percent said they would be most likely to ask a parent about the basic facts of sexual reproduction, and 60 percent said they would be most likely to ask a parent about issues related to relationships and becoming sexually active. What do teens want to know?

According to a poll conducted by the National Campaign to Prevent Teen Pregnancy, 22 percent said the one thing they would most like to discuss with their parents was knowing how and when to say "no." Twenty-one percent said they would like to know more about managing dating relationships. Another poll found that 58 percent of 10- to 12-year-olds want help from their parents in dealing with pressure to have sex.

Here's the lesson: If you want your teenagers to refrain from engaging in sex, you're going to have to overcome your own embarrassment and talk with them about it. And not just about the mechanics of sex, but also about your values and expectations about their behavior. Most especially, don't be afraid to talk to your teen about abstinence.